Year Number 2007-01-01 7.4492 2008-01-01 9.3840 2009-01-01 14.5813 2010-01-01 15.8910 2011-01-01 15.6969 2012-01-01 20.6975 2013-01-01 19.4976 2014-01-01 23.1880 2015-01-01 22.9640 2016-01-01 25.9075